Filter press



y 7, 1963 N. MALARKEY, JR 3,381,609

FILTER PRESS Filed June 20, 1966 4 Sheets-Sheet 1 w I NeilMa1C1Fkey,/J". INVENTOR.

4 Sheets-Sheet 3 N. MALARKEY, JR

FILTER PRESS May 7, 1968 Filed June 20, 1966 INVENTOR Neil M0 161 fkeg,Jn

May 7, 1968 N. MALARKEY, JR

FILTER PRESS 4 Sheets-Sheet 4 Filed June 20, 1966 Neil Mclarke pJrINVENTOR HHgrS.

United States Patent Office 3,381,609 Patented May 7, 1968 3,381,609FILTER PRESS Neil Malarkey, Jr., Rte. 2, Box 2126, Seattle, Wash. 98110Continuation-impart of application Ser. No. 388,770,

Aug. 11, 1964. This application June 20, 1966, Ser.

' 11 Claims. (Cl. 100-118) Thi application is a continuation in part ofprior filed application entitled Press for Extracting Liquids fromMixtures, filed August 11, 1964, having Serial No 388,770, nowabandoned.

This invention concerns a press for extracting liquid from aliquid-solid mixture, or from a mixture of liquid and semi-solids. Moreparticularly, the invention concerns a continuous press for performingsuch a separation.

The particular embodiment of the invention described herein comprises ajuice press that may be employed, for instance, to process pomace toseparate apple juice from pulp constituents. Features of the press, ofcourse, may have utility in other fields, and while describing the pressin connection with the extraction of juice, it is not thereby intendedto be limited only to this use.

Continuous presses for extracting liquids from liquid mixtures areknown. Many of such presses have been extremely complicated, which haslimited their usefulness. Presses of a simplier nature have either beenimpractical as a means for handling any volume of material, orineffective to produce proper filtration of a mixture whereby a clearfiltrate is obtained. Some presses have withdrawn filtrate at multiplepoints located throughout the press, utilizing complicated channels ordrains. This introduces a cleaning problem, which is particularlydisadvantageous Where food products are being handled, as periodicthorough cleaning is a necessity when handling such materials. Inpresses where relatively high pressures are developed, particularlywhere continuous operation is contemplated, pressure control has beendiflicult, and stresses have tended to develop locally in the pressultimately causing breakdown.

A general object of this invention is to provide an improved press whichtakes care of the above-mentioned diflieulties in a highly practical andsatisfactory manner.

Another object is to provide a continuous press, which has a continuousbelt providing one of a pair of opposed sides in a processing chamberfor the press, and features novel means along at least one margin ofthis belt for collecting filtrate extracted in the processing chamber.

More specifically, an object is to provide a press having means formingbarriers along one set of sides of a processing chamber, where saidchamber is defined along one (and preferably both) of another set ofside by moving belts, and the barriers constitute outer limits offiltrate zones in which filtrate collects prior to removal from thepress.

Yet another object is to provide a press where opposed and irnperforateconverging walls define a processing chamber, and at least one andpreferably a pair of opposed filter belts between these walls functionto apply pressure to the material being filtered, with filtrate thusproduced moving laterally of the filter belts into collection chambersor zones adjacent sides of the processing chamber.

A still further object is to provide a press where such filter belts arecarried on imperforate walls mounted so that opposed expanses of thewalls define a processing chamber of diminishing cross sectionprogressing from the feed to the off-bearing end of the processingchamber. In one modification of the invention these walls may constituteopposed reaches of elongated imperforate conveyor belts, while in othermodifications the walls may be the outer surfaces of cylinders.

According to the invention, elongated partitions are contemplatedextending in the direction of convergence of the processing chamber,snugly adjacent margins of such filter belts, which in conjunction withthe filter belts operate to prevent lateral flow of solid material frombetween the filter belts. Filtrate flow only is accommodated and suchflows laterally into filtrate zones disposed on opposite sides of thefilter belts.

The partitions and barriers forming filtrate zones for the collection offiltrate, may be part of elongated fingers, which themselves may be partof What is termed herein a collector in the press. The press is easilycleaned by removing the collector, and in a preferred embodiment of theinvention such removal entirely exposes the processing chamber and thezone where pressure is applied to a mixture prior to the extraction ofliquid therefrom. The collector itself is easily cleaned, beingrelatively devoid of small orifices and hard-to-clean drain passages.Fluid flow, by reason of the imperforate belts that back the filterbelts, is confined to an area between the imperforate belts and the backsides of the latter belts do not become dirtied. Pressures are developedevenly, through pressure platens which back the imperforate conveyorbelts described.

These and other objects and advantages are attained by the invention,and the same is described hereinbelow in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a side elevation of a continuous press according to anembodiment of this invention, showing a supporting frame for the pressand mounted on this frame a pair of continuous imperforate belts, havingfilter belts extending about the outside thereof;

FIG. 2 is a view, drawn on a somewhat enlarged scale, and takengenerally along the line 22 in FIG. 1, illustrating details of aprocessing chamber in the press and what is termed a collector, whichpartially defines this processing chamber;

FIG. 3 is a cross-sectional view taken along the line 3-3 in FIG. 2;

FIG. 4 is a cross-sectional view taken along the line 44 in FIG. 2, onan even larger scale;

FIG. 5 is a cross-sectional view taken along the line 55 in FIG. 2, on astill larger scale;

FIG. 6 is a side elevation somewhat simplified and on a reduced scale ofanother modification of the invention;

FIG. 7 is a top plan view of the apparatus shown in FIG. 6;

FIG. 8 is a viewon a somewhat enlarged scale taken along the lines 88 inFIG. 7;

FIG. 9 is a side view of a collector in the apparatus, on the same scaleas FIG. 8, showing the collector as it would appear viewing it from theline 99 in FIG. 7 with such removed from the apparatus;

FIG. 10 is a top view of the collector as shown in FIG. 9;

FIG. 11 is a cross-sectional view, also on a somewhat enlarged scale,taken along the line 1111 in FIG. 6;

FIG. 12 illustrates still another modification of the invention; and

FIG. 13 is a cross-sectional view, on a slightly enlarged scale, takengenerally along the line 13-13 in FIG. 12.

Referring now to the drawings, and first of all more particularly toFIGS. 1 through 5 showing one modification of the invention, a press ascontemplated herein is indicated generally at 10 (see FIG. 1). The pressincludes a main supporting frame 12, comprising a standard 14 andhorizontals 16 secured to the standard which rest on the floor.

Frame 12 supports above the fioor a pair of elongated, opposed, andsubstantially upright frame sections, designated at 20, 22. Asexemplified by the sides of the two frame sections which face the viewerin FIG. 1, these may be interconnected on each side of the press by apair of strain rods 24. The strain rods extends between the framesections, and are received within sleeves 28 joined as by welding to thesides of the frame sections. The ends of the strain rods may be threadedas at 30, and nuts 32 screwed onto these threaded ends function to holdthe frame sections from Spreading apart on the strain rods. Spacers suchas spacer 33 interposed between the frame sections hold the framesections a predetermined distance apart. Suitable bracket structure (notshown) extending between standard 14 and the strain rods on the side ofthe press away from the viewer in FIG. 1 holds the frame sections in theelevated position illustrated in FIG. 1.

In the press of the invention, opposed vertical reaches 34a, 36a ofcontinuous imperforate conveyor belts or hands 34, 36 are utilized todefine opposite sides of what is referred to herein as a processingchamber for the press, such being at the general location indicated at38 in FIG. 1. Band 34, which is shown to the left in FIG. 1, travelsover a drum or roll 40 journaled adjacent the top of frame section 20,and a drum or roll 42 journaled adjacent the bottom of this framesection. Similarly, band 36 at the right of the press travels arounddrums or rolls 44, 46 journaled adjacent the top and bottom of framesection 22.

The mountings for drums 40, 42 training band 34 may be similar to themountings for the drums training band 36. Specifically, and consideringthe drums for band 34, on each side of the press adjacent the bottom offrame section 20 is a bearing such as bearing 48 fastened to the framesection. These bearings journal a shaft 50 fastened to and extendingthrough the center of drum 42. Adjacent the top of frame section 20 oneach side of the press is a vertically adjustable bearing block 52,mounted for vertical travel on guides 54, and placed in differentadjusted positions by means of a nut 56 and threaded stud 58. Drum 40 isjournaled adjacent each of its ends on a bearing such as bearing 60, andthe inner races of these hearings are mounted on a sleeve 62 which inturn is mounted on a shaft 64. The axis of sleeve 62 is offset somewhatfrom the axis of shaft 64, i.e., the sleeve and shaft are eccentric. Theends of shaft 64 are journaled in bearing 66 mounted in bearing blocks52.

With the eccentric mounting described for upper drum 40, on turningshaft 64 the drum may be shifted toward or away from the lower drum.Each end of shaft 64 on either side of the press has secured thereto anarm 68 from which depends a weight 70. These weights exert a torque onshaft 64, whereby the same is urged to rotate in a direction causingdrum 40 to move away from lower drum 42. The Weights and the eccentricmechanism described constitute belt tensioning means operable tomaintain proper tension in band 34.

Integral with frame section 20 and facing frame section 22 is asubstantially vertical fiat faced web 76, which provides a mounting fora pressure platen 78. Platen 78 is shown attached to web 76 by fasteners80. A low coefficient of friction surfacing material may be providedover the side of the platen which faces the inside of band 34 (shown inFIG. 4 at 81), whereby the band on moving over the platen slides easilyacross the front thereof. For example, Tefion sheets may be suitablymounted over the front face of the platen to provide such a lowcoefficient of friction surface. A continuous press utilizing suchTeflon sheets is more fully described in US. Patent 3,215,065, entitledContinuously Operating Press Apparatus.

Band 34 is moved so that its reach 34a moves downwardly in FIG. 1, i.e.,in a clockwise direction, by a mo- 4 tor 82 supported on standard 14 bybracket 84. Drive is transmitted from the motor to drum 42 through agear reduction unit 86, a sprocket 88, a chain 90, and a sprocket 91.

In all material respects the mounting of band 36 on the right hand framesection 22 is like the mounting described for band 34 on frame section20. Thus, adjacent the top of the frame section is eccentric mechanism92 similar to that described in connection with drum 40 for effectingtensioning in band 34. The band is moved so that reach 36a movesdownwardly, or in a counterclockwise direction, by a motor 94, gearreduction unit 96, and chain 98. Backing reach 36a of band 36 betweenrolls or drums 44, 46 is a platen which is fastened by fasteners 102 tovertical flat faced web 104 integral with frame section 22.

The opposing faces of platens 78, 100' converge on each otherprogressing downwardly in FIG. 1, and this convergence is imparted toreaches 34a, 36a of the bands where they extend over the platens. Thesereaches of the bands, therefore, at the location of processing chamber38, constitute elongated, opposed, imperforate converging walls formingone set of sides of the processing chamber.

Referring now to FIGS. 1 and 2, band 34 has extending around the outsidethereof, and directly adjacent the band where it forms one side of theprocessing chamber, a continuous filter belt 110. The filter belt mayhave a fabric composition (a layered nylon cloth belt has beensatisfactory), and is porous and somewhat compressible. The belt issomewhat narrower than band 34, and in a transverse direction isdisposed centrally of the band so that margins 34b, 340 (see FIG. 2) ofthe band are left exposed on either side of the filter belt. Band 36 hasa similar filter belt 114 extending around its outside. In theprocessing chamber, as best seen in FIGS. 2 and 4, these filter beltstravel downwardly in positions disposed opposite each other with platens78, 100 compressing the belts together adjacent the base of the chamber.The filter belts, where they travel downwardly between the platens,define opposite sides of an elongated zone 116 for holding material tobe filtered (pomace in a press for extracting apple juice).

Filter belts 110, 114 outwardly of frame sections 20, 22 extend overrolls 118 which are journaled on adjustable brackets 119 secured to theframe sections. The rolls and adjustable brackets provide a means forproducing proper tension in the filter belts.

Considering now FIGS. 2, 3, 4, and 5, mounted between the opposedvertical reaches of bands 34, 36 is what is referred to herein as acollector 120, including elongated, opposed finger portions 122, 124 anda transverse cross piece 126 interconnecting these finger portions. Inthe embodiment of the invention illustrated, cross piece 126 is shownfastened to the finger portions through fasteners 128, 130 extending infrom the sides of the finger portions and into the ends of the crosspiece. With the collector assembled in the press, inner edges of thefinger portions lie snugly adjacent the side edges of the filter belts,and between the faces of bands 34, 36, where these faces are exposedalong side margins of the bands, as at 34a, 34b for band 34.

Each finger portion comprises an elongated outer web 136 ofapproximately trapezoidal outline. The web occupies a planeapproximately normal to the planes of bands 43, 36 where these bandsdefine the processing chamber. Along nonparallel edges of web 136 aremounted elongated sealing strips 138. With the collector mounted in thepress, the opposed sealing strips carried by the web form a seal withthe exposed margins of the bands backing the filter belts. In eachfinger portion, the web and its sealing strips function as a fiowbarrier inhibiting liquid fiow laterally outwardly beyond the locationof the Web.

Each finger portion also has a flange 140 inwardly of web 136, which issubstantially normal to web 136, and which thus has opposite facessubstantially paralleling bands 34, 36 where the bands define sides ofthe prces ing chamber. Flange 140 over each of its opposite faces isbonded by ridges 146, 147, 148, and these ridges together with web 136define a recess or pocket on each side of a finger portion, suchrecesses being indicated at 142a, 142k.

The recesses in each finger portion are provided for the purpose ofcollecting filtrate as the same is extracted from the material beingfiltered prior to removal of the filtrate from the press. The recessesin effect form two chambers on each side of the finger portion intowhich such filtrate may flow. Each finger portion is apertured as at160, and in this way the recesses on opposite sides of a finger portioncommunicate with each other. Connecting with each communicating set ofrecesses is a conduit 164 which forms a means for withdrawing filtratefrom the press.

Sealing strip 138 may have transverse extensions integral therewith suchas those shown at 150 and 152, which function to seal top and bottomregions of a finger portion to the exposed margins of the imperforatebands passing beside the finger portion.

Collector 120 is supported in the press between reaches 34a, 36a, ofbands 34, 36 by brackets such as bracket 170 provided on each side ofthe press. Each bracket 170 is mounted on a set of strain rods 24extending between the frame sections, and includes an end 172 whichextends between the imperforate bands and supports the base of anadjacent finger portion. Above end 172, each bracket has a bore 174,through which extends a fastener 176. The fastener connects each bracketwith a region of each finger portion intermediate its ends.

Cross piece 126 contains a passage 180 extending downwardly therethroughin FIG. 2. A conduit or duct 182, with one end projecting into the topof passage 180', feeds material to be filtered into zone 116 within theprocessing chamber in the press. Along the base of the cross piece, andfastened thereto by screws 183 are flexible strips 184 (which may be ofnylon or other material) having edges that slide over the faces of thefilter belts as they travel into the processing chamber. Strips 184function to seal the cross piece to the filter belts and prevent leakageof unprocessed material upwardly and around the cross piece.

Extending along the inner edge of each finger portion, along ridges 146on opposite sides of the finger portion, are a pair of elongated baflleelements 186, 188. These may be made of metal and are fastened in asuitable manner to the finger portion. The top and bottom ends of thebafile elements are bent outwardly slightly as shown by portions 186a,1861: in FIG. 2. The edges of the filter belts ride on sides of thebaffle elements on travelingthrough the processing chamber, with thebafile elements tending slightly to compress the belts in a transversedirection. The outwardly bent portions adjacent the top of theprocessing chamber funnel reaches of the belts into the position theyshould have on passing through the processing chamber.

Referring now to FIG. 5, ridges 146 on opposite sides of a fingerportion, and battle elements 186, 188 mounted thereadjacent, constitutean elongated, nontraveling ledge or partition in the press extendinglongitudinally of the processing chamber adjacent each side thereof.This ledge on the inner side bears against the filter belts, andprevents fiow of material other than filtrate laterally of the belts andinto recesses 142a, 142b. Lateral travel of filtrate from the spacebetween the filter belts is permitted, however, and in FIG. thedirection of filtrate flow is indicated by the arrows as through thefilter belts and thence about opposite faces of the ridges (which arespaced somewhat from the faces of the imperforate bands) into recesses142a, 142]). Thus the ridges and battle elements, i.e., the ledge means,function as another set of sides of zone 116 extending longitudinally ofthe processing chamber for receiving material to be filtered. This zoneis separated from recesses 142a, 14% in each finger portion, i.e., theZones for collecting filtrate, by a filtering agency in the form of thefilter belts.

Adjacent drums 42, 46, a pair of scraper blades 190 are shown mounted onframe 12, which contact the filter 'belts where they extend about thedrums and scrape solid material from the filter belts. Materialdislodged by these scraper blades may fall onto a conveyor 194, to becarried away from under the belts.

In operating the press, the material to be filtered is pumped underpressure through duct or conduit 182 into zone 116, i.e., the spacebetween the filter belts, and such material enters the zone adjacent thetop of the press where the filter .belts are spaced a substantialdistance apart. As the filter belts travel downwardly through theprocessing chamber, they carry material with them, while being forcedprogressively closer together by the platens that back up theimperforate bands. Such tends to squeeze out filtrate which flows intorecesses 142a, 1421) and thence is withdrawn through conduits 164. Solidmaterial that cannot pass through the filter belts remains between thefaces of the filter belts, and where the filter belts pass over thebottom ends of the platens this material is compacted so tightly thatsubstantially all filtrate has been removed. This residue is thencarried forwardly by continued travel of the filter belts, whence it isscraped off from the belts by the scrapers described.

Referring now to FIGS. 6 through 11 wherein another modification of thisinvention is illustrated, the apparatus may be constructed with opposeddrums or cylinders, such as those illustrated at 201, 202 and 204, 205,having outer cylindrical surfaces 201a. 202a, 204a, 265a, whichconstitute the converging walls defining the processing chamber. Filterbelts, such as those shown at 207, 208 and 210, 211, extending about thesurfaces of the drums and form the filtering agencies in the press.

Considering now specifics of such a press, in FIGS. 6 through 11 thepress is illustrated with the framework supporting the operating parts,drive mechanism, and such structure omitted, in order best to illustratethe operating principle of the press. Drums 201, 262 and 204, 295 aremounted on upright shafts 212, 213, 214, and 215, which are journaled insuitable bearings in the press (not shown) and which are drivinglyconnected to suitable drive means (also not shown) whereby the drums arerotated with drums 291, 205 rotating in a clockwise direction and drums202, 234 rotating in a counterclockwise direction. A bite or nip 217 isdefined by drums 201, 202 with the outer surfaces of these drumsconverging progressing in a direction extending toward such bite, andsimilarly a bite 219 is defined between drums 2G4, 205 with the outersurfaces 204a, 205a of these drums converging progressing toward thisbite or nip.

Mounted within the space generaly encompassed by the various drums is acollector 229 corresponding to collector discussed in connection withthe first-described modification of the invention. The collector isutilized to collect filtrate produced by the press and also functions tosupply material to be filtered into the press.

The collector comprises top and bottom closure assemblies 222, 224 whichfunction as do the finger portions of the first-described modification.The two closure assemblies are similar, and thus only one will bedescribed in detail. The assemblies themselves are mounted on a supportshaft 226, which is suitably mounted in a stationary position on theframework of the press.

Considering now the construction of a closure assembly, and withreference to assembly 222, the assembly comprises an outer web 228having, when viewed in plan as shown in FIG. 10, four projections,depicted at 228a, 228b, 228e, and 228d. These radiate out from shaft 226Which extends down through the outer web and is affixed thereto. Theedges of these projections are curved to conform to the curving outersurfaces of the drums. Below web 228 in FIG. 9, and spaced axiallydownwardly on shaft 226, is an inner web 230. This web has substantiallythe same outline in plan as outer web 228, and thus includes projectionswhich complement the projections illustrated for the outer web. Joiningthe extremities of complementing projections are plate portions, such asthose shown at 232.

Between the two webs, and radiating from shaft 226, are divider walls234. These divide the space between the outer and inner webs into fourrecesses or pockets, 235a, 235b, 2350, 235d, each of which is open whereit faces the outer surface of a drum. These pockets correspond torecesses 142a, 1421) discussed in connection with the first-describedmodification, and are for the collection of filtrate. Communicating withthese pockets are conduits 236, 238. Also shown connecting adjacentpockets in a region between the webs are apertures, such as thoseillustrated at 240.

Top closure assembly 222 is sealed to the outer surfaces of the variousdrum by means of sealing strips, such as the one shown at 242. One isprovided each edge of the outer web which extends adjacent a portion ofthe curving outer surface of a drum. As best illustrated in FIG. 9, eachsealing strip has end portions 242a, 242b which extend down along themargins of plate portions 232 joining the ends of complementingprojections of the outer and inner webs.

Bottom closure assembly 234 has inner and outer webs 244, 246 definingsimilar pockets, such as the one shown at 245. Communicating with thesepockets and providing a path for the removal of filtrate therefrom, areconduits 247, 248.

Material to be filtered is fed into the press, into the region betweenthe top and bottom closure assemblies. Thus, a passage is provided inshaft 226, shown at 250, extending to a bottom, shown at 251. Formed inthe sides of the shaft (see FIG. 11) and communicating with this passageare opposed slots, such as those indicated at 252, 253. If desired, thespace between the closure assemblies which is bounded by the drums andabout the outside of shaft 226 may be partially taken up with a guidemember 255 secured to the shaft, having an approximately diamond-shapedcross-sectional outline, as shown in FIG. 11, such member being slottedat 256, 257 with slots that communicate with slots 252, 253. In this waymaterial is permitted to flow from passage 252 to the outside of theguide member. The guide member has outer curved surfaces, shown at 255a,255b, 255C and 255d, which are adjacent the drum surfaces and whichcurve approximately as do the drum surfaces while converging on them.

Filter belts 207, 208, 210, 211, which extend about the drums passbetween the top and bottom closure assemblies with their oppositemargins riding snugly against the inner webs of the closure assemblies.The filter belts may have the construction described in connection withbelt 110, whereby the belts are of a fabric composition and are porousand somewhat compressible. Preferably each belt along the inner facethereof, when in a relaxed state, has a corrugated appearance withshallow grooves, such as those shown at 207a in FIG. 11, extendingtransversely across the inner face of the belt. These grooves facilitatefiltrate flow across the back face of a belt laterally to its sides andinto the pockets described.

During operation of the press, and referring to FIG. 11, drums 201, 204are rotated with their outer surfaces moving away from each other inthat region of the press which is located between the top and bottomclosure assemblies. Drums 202, 205 have a similar relationship in thisregard. It is preferable that the radial spacing of the drums of such apair of drums be such that the filter CTI belts on the drums becompressed tightly where the drums come together, as at region 258,shown in FIG. 11. This compression of the belts has the effect ofminimizing leakage flow outwardly from between the drums in this region.Considering drums 201, 202, the surfaces of these drums on rotation ofthe drums move away from each outwardly of the press from nip 217, andit is between such a pair of drums that discharge takes place of solidmaterial remaining after the filtering process. A similar pair of suchdrums comprises drums 204, 205. The radial spacing between two drums ofsuch a pair of drums is somewhat greater, so as to permit solid residueobtained by the filtering process to pass between the nip of the drums.

Located adjacent the outside of the press are scrapers such as thoseshown at 259 provided for the purpose of scraping solid residue from offthe belts.

Describing now the operation of the press, shown in FIGS. 61l, the innerwebs of the closure assemblies function, as do flanges 146 earlierdescribed, in forming elongated partitions within the processingchamber, which are located between the top and bottom webs of theclosure assemblies and inhibit the passage of solid material laterallyoutwardly from the side margins of the filter belts. The outer webscomprise fiow barriers forming the outer limits of the processingchamber, and as flow barriers operate to contain filtrate, whereby it isprevented from flowing outside of the region bounded by the closureassemblies. Material to be filtered is admitted through passage 250 inshaft 226, and with the drums rotated in the directions described,material tends constantly to be conveyed while being compresesd towardnips or bites 217, 219. As the material is compressed, filtrate isforced through the filter belts and thence flows laterally of the beltsinto the various pockets, whence the filtrate is collected in a suitablecollecting vessel on passing out through conduits 247, 248. Solidresidue with filtrate expressed therefrom passes through bits 217, 219,thence to be scraped off the filter belts by the scrapers described.

A still further modification of the invention is illustrated in FIGS. 12and 13. In this modification of the invention, the opposed imperforateconverging walls which form one set of sides of the processing chamberin the press are provided by the inner circumferential surface of ahollow cylinder, shown at 300, and the outer circumferential surface ofa smaller cylinder 302. These drums or cylinders may be rotated underpower, as by suitable drive means drivingly connected to shaft 304joined to drum 302, and power driven rollers 306 which engage the outercircumference of hollow drum 300. The filter belts which comprise thefiltering agency in this modification of the invention are shown at 308,310. Belt 308 extends about the outside of the smaller drum 302, whereasbelt 310 extends about the inner circumference of the larger drum 300.

In this modification of the invention, as in the first modificationdescribed, a collector is provided, designated at 312, which extendsbetween the opposed converging surfaces of the two drums. The collectorincludes a cross piece 314 corresponding to cross piece 126 of thefirstdescribed modification, and opposed finger portions 316, 318corresponding to finger portions 122, 124 of the firstdescribedmodification.

Each finger portion comprises an elongated outer web 320 approximatelynormal to the axes of the cylinders, and along the edges of web 320 aresealing strips 322. The web and its sealing strips function as a flowbarrier inhibiting liquid flow laterally outwardly beyond the locationof the web. Joined to each web is a flange 324 which is perpendicular tothe plane of the web, and ridges 326, 328. These ridges together withthe web define recesses in each finger portion, shown at 330, 332, forthe collection of filtrate. A conduit 336 for each finger portioncommunicates with recesses and provides a path for the withdrawal offiltrate.

Cross piece 314 of this modification of the invention may have aconstruction similar to the cross piece discussed in connection with thefirst-described modification. The nip of the drums, where maximumcompression of material to be filtered occurs, is indicated at 340.Progressing from this nip in the direction of rotation of the drums, thebelts diverge from each other, and solid residue is removed from thesurfaces of the filter belts through scrapers shown at 342.

The operation of this described modification of the invention is quitesimilar to the operation of the firstdescribed modification. Theconstruction has certain specific advantages, in permitting theelimination of multiple rollers for mounting the bands, and theelimination of rigid pressure platens for imparting through the bandscompression to the material being treated.

The press of the invention is characterized by a number of importantadvantages. It will be noted that in the press, by reason of theimperforate walls that carry the filter belts, there is no movement offiltrate through and to the back sides of the walls. Collection offiltrate is by means enabling lateral fiow of such material intoexpansive filtrate zones adjacent the sides of the press. These aredefined by flow barriers sealed to the exposed walls. The press isdevoid of complicated passages or ducts provided for the flow offiltrate which could present cleaning problems. When cleaning isnecessary, it is a relatively easy matter to wash the collectordescribed.

While there has been described an embodiment of the invention, it isobvious that changes and variations are possible to produce othermodifications thereof. It is desired to cover all embodiments of theinvention as would be apparent to one skilled in the art, and that comeWithin the scope of the appended claims.

It is claimed and desired to secure by Letters Patent: 1. A press forextracting liquid from a liquid-solid mixture comprising opposedconverging Walls forming one set of sides of a processing chamber ofdiminishing sideto-side dimension progressing in the direction of theconvergence of the walls, which walls are impervious to liquid flowtherethrough, at least one of said walls being movable and operating totransport material to be filtered through said processing chamber;opposed elongated flow barriers in fluid-tight relationship with saidconverging walls, extending in the direction of the convergence of saidwalls, and forming another set of sides of the processing chamber; meansextending in the direction of the convergence of said walls dividing thechamber into a filtrate zone for holding filtrate, which zone is boundedon one side by a fiow barrier, and a zone for holding material to befiltered spaced laterally from this filtrate zone; and means connectedto the filtrate zone for drawing off filtrate therein.

2. The press of claim 1, wherein said walls are cylindrical surfaces ofdrums mounted in relation to each other so that the surfaces converge todefine a nip for the drums.

3. The press of claim 2, wherein the means dividing the chamber intozones includes a filtering agency extending along at least one drumsurface.

4. A continuous press for extracting liquid from a liquid-solid mixturecomprising a pair of opposed converging walls forming one set of sidesof a processing chamber of diminishing side-to-side dimensionprogressing in the direction of the convergence of said walls, at leastone of the walls being movable and operating to transport material to befiltered through the processing chamber; a continuous filter beltextending along at least one of said walls and movable with said onewall through said processing chamber, said filter belt within thechamber defining an elongated zone extending through the chamber forholding material to be filtered; opposed elongated fiow barriers influid-tight relationship with said converging walls, extending in thedirection of the convergence of said walls, and forming another set ofsides of the processing chamber, at least one of said flow barriersbeing spaced laterally from the margins of said filter belt and definingan elongated filtrate zone disposed within said chamber located besidesaid first-mentioned zone for holding filtrate; and means connectingwith said filtrate zone for removing filtrate therein.

5. A continuous press for extracting liquid from a liquid-solid mixturecomprising a conveyor belt having an elongated reach forming one side ofa processing chamber,

an elongated wall opposite and spaced from said reach forming anopposite side of the processing chamber and said belt reach and wallconverging upon each other progressing in the direction that theconveyor belt moves,

a pair of opposed elongated flow barriers adjacent opposite side marginsand extending longitudinally of said conveyor belt reach forming anotherset of sides of said processing chamber, said flow barriers being sealedalong their lengths to said belt reach and wall,

means including a filtering agency extending along the conveyor beltwithin said chamber dividing the chamber into at least two zones onecomprising a longitudinally extending filtrate zone bounded on one sideby a flow barrier, the other zone comprising a zone for holding materialto be filtered which other zone is separated from the filtrate zone bythe filtering agency, the zone for holding material to be filtered beingspaced laterally of the filtrate zone, and

conduit means connected to the filtrate zone for drawing off filtratetherein.

6. A continuous press for extracting liquid from a liquid-solid mixturecomprising an imperforate conveyor belt with an elongated reach thereofforming one side of a processing chamber,

an elongated imperforate wall opposite and spaced from said reachforming an opposite side of the processing chamber,

opposed elongated fiow barriers adjacent opposite side margins of saidbelt reach forming another set of sides of said processing chamber, saidflow barriers including means sealing them to said belt reach and wall,

elongated nontraveling ledge means extending longitudinally of saidprocessing chamber and spaced inwardly from at least one How barrier anddefining on One side thereof and with the flow barrier a filtrate zonefor the collection of filtrate,

means including a filtering agency within said processing chambercooperating with said ledge means to define on the opposite side of saidledge means a zone for holding material to be filtered, with the latterzone being separated from the filtrate zone by said filtering agency,and

means connecting with said filtrate zone for withdrawing filtratetherein.

7. The press of claim 6, wherein the means Within the processing chambercooperating with said ledge means to define a zone for holding materialto be filtered comprises a filter belt disposed about the outside ofsaid imperforate belt, which travels through said pressure chamber onmovement of said imperforate belt.

8. The press of claim 6, wherein said one flow barrier and said ledgemeans are joined together, the flow barrier is opposite the face of theimperforate belt, and the means sealing the flow barrier comprises meansmounted on Eh? flow barrier that engages the face of the imperforate 9.A continuous press comprising a pair of imperforate conveyor beltshaving oppositely disposed elongated reaches that converge on each otherand define a processing-chamber with wide and narrow ends,

means for moving the belts with said reaches advancing in the directionthat they converge,

filter belts extending along the outside of said imperforate belts, oneon each, and movable with the belts 1 1 in oppositely disposed relationthrough the processing chamber,

an elongated partition extending longitudinally within the processingchamber snugly adjacent one set of edges of the filter belts operable toaccommodate filtrate flow laterally of the filter belts but inhibitingthe passage of solid material from between the filter belts, anothersuch elongated partition snugly adjacent the opposite set of edges ofthe filter belts,

opposed flow barriers adjacent opposite side margins of said beltreaches forming a set of sides for said processing chamber locatedlaterally outwardly of said partitions, said flow barriers includingmeans whereby they are sealed to opposite reaches of the belts, and saidflow barriers adjacent the sides of the belt reaches defining a filtratezone for collecting filtrate, and

means connected to said filtrate zone for withdrawing filtrate therein.

10. The press of claim 9, wherein a partition and fiow barrier on eachside of the processing chamber are joined together as an elongatedfinger with said finger mounted in a stationary position between facesof the opposed imperforate belt reaches.

11. A continuous press comprising a pair of imperiorate conveyor beltshaving oppositely disposed elongated reaches that converge on each otherand define a processing chamber,

means for moving the belts with said reaches advancing in the directionthat they converge,

filter belts extending along the outside of said imperforate belts, oneon each, and movable with the belts in oppositely disposed relationthrough the processing chamber,

an elongated partition extending longitudinally within the processingchambers snugly adjacent one set of edges of the filter belts operableto accommodate filtrate flow laterally of the filter belts butinhibiting the passage of solid material from between the filter belts,another such elongated partition snugly adjacent the opposite set ofedges of the filter belts, and means for collecting filtrate which flowslaterally of the filter belts.

References Cited UNITED STATES PATENTS 1,778,342 10/1930 Thompson100-118 X 1,997,611 4/1935 Thompson 100120 X Re. 21,723 2/1941 Thompson100120 X 2,308,031 1/1943 Schmitz 100121 2,382,453 8/1945 Thompson100-418 X 2,682,832 7/1954 Lohre et a1 100121 2,981,307 4/1961 Malarkey100154 3,104,608 9/1963 Ribbans 100-154 X 3,215,065 11/1965 Malarkey100-154 X 3,269,303 8/1966 Qviller 100-121 FOREIGN PATENTS 28,844 6/1957Finland. 572,324 2/ 1924 France.

LOUIS O. MAASSEL, Primary Examiner.

1. A PRESS FOR EXTRACTING LIQUID FROM A LIQUID-SOLID MIXTURE COMPRISINGOPPOSED CONVERGING WALLS FORMING ONE SET OF SIDES OF A PROCESSINGCHAMBER OF DIMINISHING SIDETO-SIDE DIMENSION PROGRESSING IN THEDIRECTION OF THE CONVERGENCE OF THE WALLS, WHICH WALLS ARE IMPERVIOUS TOLIQUID FLOW THERETHROUGH, AT LEAST ONE OF SAID WALLS BEING MOVABLE ANDOPERATING TO TRANSPORT MATERIAL TO BE FILTERED THROUGH SAID PROCESSINGCHMBER; OPPOSED ELONGATED FLOW BARRIERS IN FLUID-TIGHT RELATIONSHIP WITHSAID CONVERGING WALLS, EXTENDING IN THE DIRECTION OF THE CONVERGENCE OFSAID WALLS, AND FORMING ANOTHER SET OF SIDES OF THE PROCESSING CHAMBER;MEANS EXTENDING IN THE DIRECTION OF THE CONVERGENCE OF SAID WALLSDIVIDING THE CHAMBER INTO A FILTRATE ZONE FOR HOLDING FILTRATE, WHICHZONE IS BOUNDED ON ONE SIDE BY A FLOW BARRIER, AND A ZONE FOR HOLDINGMATERIAL TO BE FILTERED SPACED LATERALLY FROM THIS FILTRATE ZONE; ANDMEANS CONNECTED TO THE FILTRATE ZONE FOR DRAWING OFF FILTRATE THEREIN.